Source – SV Verification Directory

Class

A class is a user-defined data type that serves as a blue-print for creating objects. A class includes properties(variables) and methods(functions and tasks) that manipulate data.

Example: Class

class Ex_class;
   // class properties or variables
  int a, b, s;

   // task method
  task sum (int a,b);
    s = a + b;
    $display("a = %0d , b = %0d, sum s = %0d", a, b ,s);
  endtask

endclass

A class can be defined and used in a program, module, package, or outside of any of these. A set of classes can be grouped in a package.

// class in a package
// file pack.svh
package group_classes;
   class Ex_class;
      // class body as defined above
   endclass
endpackage

// import a package in a program
program automatic test;
   import group_classes::*;
   Ex_classes cl;
   // code
endprogram

Parameterized Class

Parameterized classes are similar to parameterized modules in Verilog.

Syntax

class para_class #(parameter N = 4);
   logic [N-1:0] data;

   function new();
      data = 8;
   endfunction
endclass